


Marvel Parasitic Twin Soulmate AU

by BaronVonChop



Category: Marvel Cinematic Universe
Genre: Alternate Universe - Soulmates, F/M, Fluff, M/M, Parasitic Twin Soulmate AU, Soulmate-Identifying Marks, Soulmates, mild body horror, parasitic twins
Language: English
Status: Completed
Published: 2019-03-08
Updated: 2019-03-08
Packaged: 2019-11-13 23:24:56
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,020
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/18041090
Author URL: https://archiveofourown.org/users/BaronVonChop/pseuds/BaronVonChop
Summary: A Marvel Soulmate AU where everybody in the world is born carrying their soulmate’s parasitic twin. Mild body horror, but mostly odd fluff.





	Marvel Parasitic Twin Soulmate AU

**Author's Note:**

> For the basics of a parasitic twin AU, please see:  
> <https://baronvonchop.tumblr.com/post/182334942888/soulmate-au-where-everyone-has-a-parasitic-twin>

For most of his youth and young adulthood, Tony Stark doesn’t spend much time worrying about his soulmate. He figures he doesn’t need a soulmate to have a good time. He might stumble across his soulmate someday, and there are plenty of good-looking people happy to keep him busy in the meantime.

Occasionally, when feeling pensive, he lies in bed poking at the parasitic twin growing from his chest, with the little leg growing from it. One day, he is in bed with two gorgeous brunettes when his parasitic twin suddenly grows green and larger, with bulging muscles and thick veins. Tony runs from the room as the brunettes start to scream.

The brunettes leave, so Tony wraps himself in a blanket and turns on the TV for a good sulk. There are news reports on every station about something big and green attacking Manhattan. Suddenly Tony is very interested in his soulmate.

Tony gets to work investigating his soulmate by running tests on his PT. He learns that it shows traces of intense gamma radiation exposure, which leads him to rumors of top-secret military tests.

When Tony tracks him down, Bruce at first insists that he has no idea what Tony is talking about. When that doesn’t work, Bruce worries that Tony will turn him in, which starts to make him angry. As Tony plies him with questions, Bruce calms down, distracted by all the science.

As their talk shifts to their PTs, Bruce admits that he always wondered why his PT was so gropey. Tony laughs, but has the good grace to look embarrassed.

Tony looks at the little hand on Bruce’s PT. “You know I’m going to have to make a tiny Iron Man gauntlet for it, right?”

Bruce pauses. “What?”

“Oh yeah, I forgot to say. I’m Iron Man.”

* * *

Growing up together in Brooklyn, Steve and Bucky get into plenty of scrapes where they see each other’s PTs. They have known each other all their lives, so it’s not that strange. Neither one can really pinpoint the moment when they recognize the resemblance between their PTs and each other. The realization sort of dawns on them naturally, as their friendship and trust in each other grows.

Bucky never teases Steve about the skinny leg emerging from the PT on Bucky’s side. Steve sometimes jokes that the arm on the PT on his stomach is the only muscular thing about him.

That certainly changes when Steve receives the super soldier serum. Bucky watches, eyes wide, as his PT’s suddenly muscular leg flexes, muscles bulging. When Steve becomes Captain America, Bucky buys an American flag handkerchief and makes the leg a little sleeve-like costume. Steve finds it hilarious.

During the war, when they are separated by combat assignments, they hold their PTs close, touching them like talismans, knowing that the little kicks and punches they feel mean that their soulmates are still fighting.

After Steve’s plane goes down, Bucky’s PT goes cold to the touch. It seems fitting, as Bucky gets drawn into darker places and becomes the Winter Soldier.

When Steve awakens, he wonders why his PT is still so active, almost as if Bucky were still caught in a war. He figures Bucky’s fighting spirit lives on in his PT.

When he meets Bucky again, he realizes how wrong he was. It is painful to feel his PT writhing in torment after each of their fights. He knows how it must be tearing Bucky up inside, what they are making him do.

When Bucky’s handlers decide to remove his PT to get him back under control, Bucky finds the strength to throw off the shackles they have placed on his mind. His PT is damaged, but he manages to escape. When he meets Steve again, they both know that their connection is not as strong as it was, but they embrace and vow to fight to stay together and rebuild what others had tried to take away.

* * *

Shuri is curious about her PT. The little foot is scrawny, and it curls up in sadness so much that Shuri wonders what kind of life her soulmate must be having. She reads a lot of books, so she wonders if perhaps her soulmate is a prisoner somewhere, or a lonely orphan living on the street.

She wonders what must have happened when one day the foot gains wiry muscle. She doesn’t even know what to think when, as she tries to get out of bed the next morning, she finds that her bedsheet is stuck to her PT.

Naturally, she goes to her lab for answers. A rigorous round of testing reveals intriguing results. Before she can uncover the answer, it finds her, when she hears others in the lab discussing someone called Spider-Man.

But who is Spider-Man really, and how can she meet him? Given Wakanda’s isolation, she can’t exactly fly to New York to look for him, even though she finds herself thinking about it from time to time.

Then one day her brother’s colleague Tony Stark comes to visit Wakanda, bringing with him a young intern of his. When her brother asks her what he should get them as welcome presents, she laughs and jokes that they need Wakandan sandals like the ones he wore to her lab. Naturally, being T’Challa, he takes her up on the idea.

Shuri laughs uproariously to see these two Americans wearing the dorky sandals, but her eyes go wide and her laughter turns into the loudest gasp when she recognizes Peter’s foot from her PT.

Shuri grabs Peter by the shirt and pulls him close. He starts to apologize, thinking he has done something wrong. She tries to ask “Are you Spider-Man?” but she is so excited that she can’t think, so she ends up shouting, “Are you sticky?”

Tony never lets Peter live it down.

* * *

Jane grows up wondering why her PT is so buff, and more importantly, why nothing seems to hurt it.

Until one day when her truck hits a strange man in a storm, and she runs over to him, looks down, and says, “Oh.”


End file.
